Shock absorber



Nov. 6, 1928.

J. R. SNYDER SHOCK ABSORBER Filed Aug. 9, 1924 2 Sheets-Sheet 1 J. R.SNYDER SHOCK ABSORBER Nov. 6, 1928. 1,690,256

Filed Aug. 9, 1924 2 Sheets-Sheet 2 -oanoavra"". .II'II'IIIII PatentedNov. 6, 1928.

UNITED.S.TATES PATENT OFFICE."

aAooB R; SNYDER, or CLEVELAND, OHIO, ASSIGNOR 'ro THE STAR REBOUND, con-TROLLER COMPANY, or CLEVELAND, OHIO, A oonrortnrrolv or OHIO.

SHOCK ABSORBER.

Application filed August 9, 1924. Serial 210/731 014.

This invention relates to shock absorbers adapted especially for use onmotor vehicles, andlias for its chiefobjectthe provision of a shockabsorber of the friction retarded type which combinesthe features ofcheapness in construction and efiiciency in action More particularly itis theobject to provide a shock absorber of the type having africtionally retarded drum adapted to accommodate a belt or strapdesigned to be wound onto and unwound therefrom, but which doesnotrequire a'casingto enclose the drum-and other parts such as thespring which is associated with the drum, the inner portion ofthe belt,and

the members which frictionally oppose the .movement of the drum. i

More specific objects are to provide means whereby the parts requiringlubrication can be supplied with lubricant without liability 2 of. thelubricant being lost, also to exclude dirt and other foreign matter frombetween therelatively moving surfaces such as the friction members andthe portions of the :drum which these members engage, and additionallyto provide a construction which is not only inexpensive, but wherein'theparts can be readily assembled and disassembled.

Theinvention may be briefly summarized as consisting in eertainnoveldetails of coni a struction, and combinations and arrangements ofpartswhich will be described inthe specification and set. forth in theappended claims. a

In the accompanying sheets of drawings wherein I have shown thepreferred construction'and a modification as to one feature thereof,Fig. 1 is aweytical sectional view through the shock absoi'ber; 2 is asectional View at right angles to the section in .Fig. 1; Fig. 3 is aView partly inelevation and partly in section illustrating a modifiedarrangement and manner of connecting certain metallic and non-metallicportions of the drum: Fig. 4 is a detail sectional viewalong 4:, theline 4 of Fig. 2; Fig. 5 is a detail sectional view along the line 5-5of Fig.6; Fig. dis a side elevation of the shock absorber shown in 1Fig. 7 is an inner facevi'ew of a portion of the drum of F igf3illustratinga manner in which the wooden membersmay be con nected to.the outer metallic portion of the drum so asto permit a neutral zone ora slight relative movement between these parts for a purposeto-beexplained; Fig.8 is a similar 56 View showing a modification of thisfeature;

and Fig. .9 is a sectional View substantiall along the line 99 of Fig.8.

-The shock absorber includes a stationary center bolt 10, havinganon-circular enlarged middle portion 10 preferably hexagonal incross-section and provided at one end with a relatively long threadedportion 10 by which the center bolt may be attached to a suit-ablefitting'to connect it-to-the chassis frame of the vehicleyassuming-thatthe shock jabsorber is employed for motor vehicle'use." At the otherside of the middle portion 10 :is a relatively short threaded end 10." i

Surrounding the relatively large: middle I portion 10-of the'center boltis a stationary. collar: 11, preferably formed in two halves, this"collar serving as a support for a spring as well as a bearing member forthe drum.

It: might be here stated that the shock absorber to which the featuresof my invention are' applied most advantageously is of the type whichcomprises a drum rotatable about the center bolt in opposite directions,a belt which iswound part way around the drum, and has one end connectedthereto while the other end is connected to the axle of the vehicle, orother suitablepart in the event the shock absorberis not employed formotor vehicle use. Vhen the bodyandaxle ap-- proach each other, orduring-the compresfore retards the rebound movement, but additionall'ythe movement of the'drum in both directions is opposed frictionally byone'or more members which engagethe drum under I certainpressure whichpermits movement of the drum in either directiombut under apredeterminedfrictional. resistance. r In 'the present construction the drum ishollow and encloses the shock absorber spring, and additionally it ispreferably a composite drum, being composedin part of non-metallicself-lubricating members, and one ormore metallic members.- In thepresent instance, the drum is composed of two non-metallic side members12, preferablyof oil impregnated wood, and anoute r metallic portionwhich joins the members 12' and receives the belt 13.

The metallic portion of the drummay he (ill composed of a single unit orpart, or of two or more parts. In the construction which is preferred,for the reason that I find it to be the least expensive, the metallicportion of the drum is composed of two spaced sheet metal disks 14 whichare secured to or carried by the non-metallic or wooden disks 12 andaring or annulus 15 which unites the two members 1 1 and on which thebelt 13 is wound during the compression stroke of the main springs andfrom which it is unwound during the rebound stroke.

As herein illustrated, the metal disks 14 engage the inner sides of thewooden disks 12, and in the preferred construction which. I haveillustrated in Fig. 1, they are secured to the inner sides of the disks12. They can be secured in place in various ways, but an inexpensive wayis to provide spurs 14 on the disks lei which can in the process ofassembling be pressed into the wooden disks 12. Preferably the inneredges or peripheries of the disks ll engage shoulders 12 on the innersides of the disks 12, and just outside of the disks 12 the disks 14 arecurved laterally outward to provide shoulders 1 1" which engage on theperipheral portions of the disks 12 and assist in transmit-ting to thelatter the load created by the pull on the strap or belt 13.

The disks 14 and the band or annulus 15 can be fastened together invarious ways, but preferably by providing on the edges of the band 15lugs 15 designed to project through suitably located openings near theouter edges of the disks 14, and by slightly riveting or upsetting theends of the lugs. It might be here stated, however, that in view of themanner in which the friction disks, hereinafter referred to, engage thewooden disks 12, the upsetting of the ends of lugs 15 is not necessaryto retain the parts of the drum in proper assembled relationship.

Preferably the band 15 is supported on the disks 14, a slight distanceinwardly from the outer edges of the disks 14, so as to leave beyond theband 15 outwardly extending flanges 14 which serve as guides for thebelt or strap 13, as clearly illustrated in Figs. 1 and 3. Additionally,I prefer that the disks Isl be given the equivalent of a compound curvebetween the wooden disk 12 and the band 15, so as to provide annularshoulders 14 constituting seats for the band 15, this latter featurebeing desirable to minimize the liability of leakage of lubricant fromthe interior of the drum.

The annular disks 1 1 are punched from sheet metal and in one operationthey can be blanked out, curved to provide the shoulders 14" and 14 andthe openings punched which receive the lugs 15 of the band 15. The band15 is formed from a strap of sheet metal of suitable length which isformed into annular shape and its ends fastened together in any suitableway as by welding. I prefer to bend the ends of the straps laterallyoutward and weld the ends together, face to face, as illustrated at 15in Fig. :2, forming an outward extension or protuberance for a purposeto be explained.

The spring which is located in the drum and rotates the drum in onedirection to wind the st 'ap thereon, as previously explained, is shownat 16, this spring being preferably formed of flat stock into spiral orclock type form. The inner end of this spring is fastened to the collar11, preferably by extending its inner end into an opening thereof asillustrated in Fig. 2. The outer end of the spring is attached to theband 15 of the drum as is also the inner end of the strap 13. Preferablythe outer end of the spring and the inner end of the strap are socuredto the band 15 by a single bolt 17 or equivalent device which passesradially through an opening of the band as clearly illustrated in F 2.With this construction the end of the spring is hooked over the innerend of the bolt and lies between two shoulders 17 located on the innerside of the band, the outermost shoulder engaging the latter and theportion of the bolt projecting outwardly through the band passes throughthe end of a metal clip 18 riveted or otherwise secured to the end ofthe strap 13, the parts being held in this relationship by a nut 17screwed on the bolt 17.

The bolt 17 passes through the band close to the protubcrances 15"formed by the ends of the strap of which the band 15 is formed, theprotuberance being located on the opposite side of the bolt from that inwhich the strap 13 extends from the bolt. This protuberance thereforeprevents the strap being applied in the wrong direction to the drum, andmakes it impossible for the parts to be assembled in'iproperly by aninexperienced person.

The last or outer convolution of the spring is preferably supported andheld from sagging 0r bending inwardly as when the spring, is tightlywound up, and this is preferably accomplished by providing between thedisks 14; a cross-piece 19 (see Figs. 2 and 4) over which cross-piecethe last convolution of the spring extends as illustrated in Fig. 2.This prevents the bending of the spring adjacent the bolt 17 and therebyincreases its life and keeps the body of the spring substantiallyconcentric with the center bolt when the spring is fully wound up.

The rotation of the drum in both directions is retarded by twostationary friction disks 20 which engage the outer sides of the woodendisks 12. One of these friction disks 20 is solidly clamped against ashoulder 10" of the center bolt by a nut 20 which is screwed onto thethreaded end 10 of the center bolt, while the other friction disk 20fits onto the bolt and is pressed yieldingly inward under adjustablespring pressure, so it as to provide the desired pressure between thetwoqfriction disks and the disks 12 of thedrum which they engage..Difierent. kinds :of springs may be employed forathis purpose but inthis instance I show aspring 2lvpunched from sheet metal and suitablytempered, this spring bc .ing. preferably of the star type with spacedarms engaging the adjacent frictiondisk 20, as illustrated; Thisstarspring 21, which fits over the relatively short threaded end 10 of the".center 'bolt, is caused to bear with the desired "pressure against theadjacent disk 20 by means of a nut 22 which is screwed onto the end 10?of the'center bolt. =A sheet metal ing mark as shown-at 23 in Fig.6,-which by ltS'POSllZlOIl with reference to the fingers or armsof thestar spring serves as an indicae tion'of the tension which lSillDPOZQdin the star spring' vg 1 ,The' wooden disks 1 12. of the drum. havetheir outer surfaces taperedinwardly and r the triction disks20'c1onfor1n to thistaper so that the friction disks serve to supportthe drum as well as to frictionally resist its movement, The innerportions of the disks 12 where they fit onto the collar 11 arerelatively narrow and while theinner portions have a bearingionthecollar 11,,the principal bean ing is provided by the friction disksso that wear on; the inner portions of the. disks .12,

where they engagethe collar will not disturb the concentric relationshipbetween the drum and the. center bolt, 7 ,1 i

. It'i'night be noted that the friction disks Y extend along the outertapered faces Qof the Wooden disks 12 and extend inwardlya suitabledistance over the perlpheralportions of the disks 12 as indicated at20". This eifectively prevents dirt and other foreign material enteringbetween the, friction disks and the-disks 12. of the drum. I

It is desirable that lubricant be supplied to the interior of the drumto lubricate thecon' volutions of the spring so as to render itnoiseless. This can be supplied by a suitable grease; gun or inanyotherway into an openinglO of the, Centerbolt, which opening is.normally'closedby a plug 24. -This opening near its inner endcommunicates with a transverse :opening '10 communicating with an,

sorber the right hand-friction disk 20 (as the parts are viewedinFig. 1) is first slipped onto the threaded nut 10 of thecenter boltand fastened in place by the nut then theright hand disk 12 of the drum,right hand piecelll of the collar and-therig'ht "I hand metal disk 14are applied then the.-

spring- 16' is applied, after which the other parts are applied inorder. Then by placing the parts thus loosely assembled into a press thespurs 14 of the metal disks liiare caused to be embedded into thewoo'dendisk 12. and,

at the sametime, or subsequently, the ends of thelugs 15 are upset tomake a permanently tight construction of the-drum then when the starspring21. is placed under suit able tension and theistrap l3 isapplied,-the deviceis ready for use. It might be here stated that thecollar .11 has peripheral flanges-11 which prevent the inner portions ofthe wooden disk 12 at any time engaging the spring 16. q i I Shockabsorbers of the type described are generally shipped from the-factoryin condi tion to be applied tothe cars, and in that event the springs16. are" wound up to the extent required for application to a car. Thismakes it necessary that some suitable means be provided to hold the drumagainst rotation relative to the friction" disks until the shockabsorber is applied to'the car.

This has. been readily. accomplished heretofore when the shockabsorberincluded asia part of the construction a: stationary casingenclosing the "drum, by simply pulling outt-he strap :to the requiredextent on a suitable machine and by extending a nail or equivalentdevieethrough the strap on the outside of the casing so as to prevent thestrap being providingon one side of the drum a stud or rivet 25 and bymounting on the shank of the'rivet a cam shaped. holding member 26 witha toothed periphery, the teeth of this member biting into theperipheral-part 20 ofthe adjacent friction disk (as illustrated in Fig.5) and thus holding thedrum against rotation until after the shockabsorber'is attached to a. car,'wh'ereupon the locking member 26 isremoved and is no longer.

neededw i g I With the-construction described above, the

parts 12, 14 and 15 of the drum are rigidly fastened togetherandtherefore every movement in either direction imparted to the peripheralpart of the drum by the strap 13 or spring 16, is frictionally retardedby the friction disks 20; therefore, minor vibrations or relativemovement between the axle and car body are retarded as well as the moreextensive relative movements. It may be desirable, however, that theminor vibrations or relative movements between the car body and runninggear be unretarded or uninfluenced by the shock absorber as when the caris traveling over a fairly smooth road. In the modificationsillustrated, Figs. 3, 7 8 and 9 show a construction wherein what I termthe minor vibrations are not frictionally retarded. This is accomplishedby so constructing the drum that a predetermined free relative movementis permitted between the inner portions of the drum which the frictionmembers engage and the outer or metallic portion of the drum to whichspring 16 and strap 13 are attached. In accomplishing this result thespurs 1-1 or whatever equivalent devices may be employed to rigidlyfasten the disks 12 to disks 14 are eliminated, but the metal disks,here designated 14, engage the inner sides and the peripheral portionsof the wooden disks, here designated 12", substantially as in theconstruction first described, and the metal disksengage the wooden disksfreely enough so that the iformer may have a certain slippage relativeto the latter. To permit this without undue friction, the disks 14extend inwardly along the inner sides of disk 12 a shorter or lessdistance than in the construction first described, as will be apparentby comparison of Fig. 3 with Fig. 1, and if necessary, the lateralcurving to form the seats or shoulders '14" may be extended laterallyoutward a somewhat greater distance to provide a firm seating of themetal part of the drum on the wooden disks. This will be apparent-alsoby a comparison of Fig. 3 with Fig. 1.

To permit the predetermined relative movement between the outer andinner portions of the drum, and then to cause the rotation of the outerpart to betransmitted to the inner or frictiomrlly retarded part,various constructions may be utilized. For example. in Figs. 3 and 7 thedisks 14* are provided with studs 14" which extend into are shaped slots1E2 provided on the inner sides of the wooden disks 12. In theconstruction illustrated in Figs. 8 and 9 the metal disks 14 areprovided with outwardly pressed protuberances i l which engage in areshaped notches or recesses 12 formed on the inner sides of the disks12*.

Obviously with either construction during certain minor relativevibrations between the car body and the running gear, the studs l4; ortheprotuberances 14 ofrthedisks 14* will swing freely in the slots 12'or 12' without imparting movement to the wooden disks 12. On the otherhand, when the studs or protubcrances reach the ends of the slots 12 ornotches 12', the movement of the outer part of the drum is imparted tothe wooden disks. In other words, though what may be termed a neutralzone is provided, in the limits of which no movement is imparted to thefrictionally resisted portions of the drum, nevertheless when thevibrations or relative movements between the car body and the axle orrunning gear reach a given amount, then the inner or frictionallyretarded portions of the drum as well as the outer portions are retardedand the shock absorber functions as with the construction firstdescribed.

lVhile I have shown'two ways in which the outer part of the drum mayrotate a given amount relative to the wooden portions and then with thelatter, other ways of accomplishing this result may be employed if founddesirable.

Having described my invention, I claim:

1. In a shock absorber, a rotatable drum, a spring adapted to rotate thedrum in one direction, a strap adapted to be wound onto and unwound fromthe drum, said drum being composed of a pair of non-metallic sidemembers by which the drum is supported and a metallic outer portion withside portions engaging the non-metallic side members.

2. In a shock absorber of the type having a friction retarded rotatabledrum and a strap adapted to be wound onto and unwound from the drum, adrum composed of a pair of nonmetallic side members which forms thebearing portions of the drum and an outer metal portion having sidemembers engaging the inner sides and periphery ofthe non-mctal1icmembers.

3. A shock absorber comprising a rotatable hollow drum composed of apair of nonmetallic side members by which the drum is supported and ametallic outer portion having a peripheral member and side membersengaging the non-metallic side members, a pair of friction membersengaging the nonmetallic side members, a spring housed in the drum andconnected thereto, and a strap adapted to be wound onto and unwound fromthe drum.

4. In a shock absorber, a. drum composed of a pair of nonanetallic sidemembers. a pair of metallic outer side members engaging the outerportions only of the first-named and a peripheral portion or bandconnected to and seated upon "the second-named side members, a springhoused within the drum, a strap connected to the drum, and means forfrictionally retarding rotation of the drum.

5. In a friction retarded shock absorber, a drum composed of anon-metallic side memher and a metallic outer portion, a strap en- Ill)gaging the latter, a spring for rotating the drum in one direction, anda friction plate or disk engaging the side and peripheral portion of thenon-metallic member.

6. In a friction retarded shock absorber, a hollow drum composed of apair of nonmetallic side members and a metallic outer portion, a strapengaging the latter, and a pair of friction plates or disks engaging thesides and extending inwardly over portions of the periphery of thenon-metallic members.

7. A shock absorbercomprising a hollow composite drum composed of twooil impregnated wood side members, a metallic outer portion engaging theinnersides of said side members, a strapconneoted to said outer portion,a spring housed within the drum, and

two stationary friction disks extending along nected, a spring forrotating the drum in one direction, a friction member engaging the drum,and means for forming a temporary lock between the drum and frictionmember to hold the drum against rotation when the spring is wound up.

9. A shock absorber comprising a rotatable drum having a strap woundthereon, a spring for rotating the drum in one direction, a triotionmember engaging the drum to frictionally retard its rotation,and alocking device carried by the drum and adapted to engage the frictionmember to temporarily hold the her and a metallic outer portion, a strapengaging the latter, a spring for rotating the drum in one direction,and a friction plate or disk engaging the peripheral portion of thenon-metallic member.

In testimony whereof, I hereunto afiix my signature. I

JACOB R. SNYDER.

